Browse the evidence

LCHF diets may increase mortality risk and cause adverse effects on cardiovascular and gut health due to reduced fiber intake and high fat content.

Be cautious with long-term LCHF diets. They may increase your risk of mortality and harm your gut health due to low fiber. Prioritize a diet rich in fiber and whole grains for long-term cardiovascular and gut health.

Acute creatine monohydrate supplementation reduces whole-body protein breakdown and leucine oxidation in men, but does not increase mixed-muscle protein synthesis.

If you are a man, acute creatine loading (20g/day for 5 days) may help preserve muscle protein by reducing breakdown, without necessarily increasing synthesis rates. This effect was not seen in women in this study. Ensure you are well-hydrated and follow a loading protocol if you want to maximize muscle creatine stores.

Glucose and insulin directly regulate fat oxidation by inhibiting the entry of long-chain fatty acids into the mitochondria, independent of plasma fatty acid availability.

High carbohydrate intake combined with insulin secretion can directly shut down fat oxidation in muscles, even if you are not eating fat. This happens because insulin and glucose inhibit the transport of fat into the mitochondria where it is burned. To maximize fat oxidation, one must manage carbohydrate intake to avoid high insulin spikes, as simply eating low-fat does not guarantee fat burning if insulin levels are elevated.

Exogenous infusion of sodium-3-hydroxybutyrate (ketone bodies) in healthy humans significantly reduces myocardial glucose uptake and increases myocardial blood flow.

For healthy individuals, raising ketone levels (e.g., through fasting, ketogenic diet, or supplementation) shifts the heart's fuel source from glucose to ketones and increases blood flow to the heart muscle. This metabolic shift may be beneficial for cardiac efficiency and health, particularly in conditions where glucose utilization is impaired or blood flow is restricted.

Huntington disease patients exhibit an early systemic hypermetabolic state characterized by significantly lower plasma levels of branched-chain amino acids (BCAAs: valine, leucine, isoleucine), which correlates with weight loss and disease progression.

For individuals with Huntington's Disease, weight loss is driven by a systemic metabolic defect (hypermetabolism) rather than just low food intake. This involves the rapid breakdown of muscle protein (BCAAs) to fuel the brain. Standard nutritional advice to 'eat more' may be insufficient without addressing the underlying metabolic energy deficit. Monitoring BCAA levels could serve as a biomarker for disease progression.

Combining metformin (2,000 mg/day) with exercise training does not enhance whole-body insulin sensitivity in individuals with prediabetes compared to exercise training alone, and may blunt the full effect of exercise.

If you have prediabetes, exercise training significantly improves your insulin sensitivity. Adding metformin does not provide extra benefit for insulin sensitivity and might actually reduce the gains you get from exercise. Focus on consistent exercise (aerobic and resistance) as the primary driver for improving insulin sensitivity, and discuss with your doctor whether metformin is necessary for other reasons (like weight loss or diabetes prevention) rather than expecting it to boost exercise benefits.

Lean individuals (BMI < 25 kg/m² for Caucasians, < 23 kg/m² for Asians) with NAFLD face a higher risk of severe liver disease and mortality compared to obese NAFLD patients, challenging the belief that lean NAFLD follows a benign clinical course.

If you have fatty liver but are not overweight, do not assume your condition is mild. You are at higher risk for severe liver complications than obese patients with fatty liver. You require regular monitoring for fibrosis progression and metabolic health, just as strictly as obese patients.

In lean individuals, the PNPLA3 rs738409 G allele is an independent predictor of NAFLD and NASH severity, whereas it is not associated with histological severity in obese patients.

If you are lean and have fatty liver, genetic testing for PNPLA3 may help predict your risk of progression to NASH. This information can guide how frequently you need liver biopsies or advanced imaging, even if you maintain a healthy weight.

As national GDP per capita increases, the prevalence of overweight and obesity shifts from being concentrated in the wealthiest population deciles to the poorest deciles, driven by rising obesity rates among the poor rather than declining rates among the wealthy.

Public health policy in developing nations must anticipate that obesity will increasingly become a disease of poverty, not wealth. Interventions should target the poor, focusing on affordable healthy food access and physical activity opportunities, rather than assuming the wealthy are the primary at-risk group.

Modifying food retail access (availability, proximity, or price) does not have a profound or independent effect on dietary consumption or obesity levels.

Simply building a supermarket in a food desert is unlikely to solve obesity or improve diet quality on its own. If you are on a tight budget, focus on 'economy' lines which can be as healthy as standard products, and prioritize food budgeting strategies over relying on the proximity of a single store type.

Thyroid hormone (TH) signaling is a primary regulator of basal metabolic rate and energy expenditure, with severe hypothyroidism capable of slowing total body energy expenditure by up to 50%.

Your body's metabolic rate is not fixed; it is actively regulated by thyroid hormones. In states of low energy availability (like fasting or severe hypothyroidism), your body slows down energy expenditure to conserve resources. Understanding this hormonal link helps explain why metabolic rate can fluctuate based on energy intake and health status.

Brown adipose tissue (BAT) is a targetable site for adaptive thermogenesis in adult humans, where thyroid hormone signaling is required for its differentiation and function, specifically through the induction of UCP1 expression.

Adult humans can possess metabolically active brown fat, which helps burn energy as heat. This process is regulated by thyroid hormones and involves a protein called UCP1. While not a primary weight-loss strategy for everyone, understanding BAT highlights the complexity of fat tissue and its role in metabolism.

Aging is associated with profound changes in epigenetic patterns, including genomic hypomethylation and promoter-specific hypermethylation, which may contribute to age-related diseases like cancer and neurodegeneration.

Understand that aging involves natural epigenetic shifts. While you cannot stop aging, dietary choices can influence these epigenetic patterns, potentially supporting healthy aging and reducing disease risk.

In the context of Nonalcoholic Fatty Liver Disease (NAFLD), hepatic triglyceride accumulation acts as a hepatoprotective buffering mechanism against lipotoxicity; inhibiting triglyceride synthesis (e.g., via DGAT2 inhibition) exacerbates liver damage and fibrosis despite reducing steatosis.

If you have fatty liver, simply trying to 'burn off' liver fat without addressing the underlying insulin resistance and free fatty acid overflow might be counterproductive. The liver uses triglyceride storage as a safety buffer. Focus on reducing the influx of fatty acids (through caloric restriction and managing insulin resistance) rather than aggressive interventions that might disrupt this buffering capacity, as this can worsen liver inflammation and fibrosis.

Pharmacological inhibition of hypothalamic Sirt1 reduces food intake and alters melanocortin system synaptic connectivity by decreasing Agrp neuron activity.

This research identifies a specific brain pathway where inhibiting the enzyme Sirt1 reduces food intake in mice. It does not currently translate to a human supplement or drug recommendation, as the effects are specific to hypothalamic neurons and involve complex neural circuitry. Caution is advised against interpreting 'Sirt1 inhibition' as a general weight-loss strategy without understanding the specific neural context.

Sirt1 activity in Agrp neurons is required for normal ghrelin-induced neuronal firing and food intake.

This finding highlights the critical role of Sirt1 in Agrp neurons for processing hunger signals (ghrelin). It suggests that genetic variations or dysfunction in this specific pathway could impact hunger regulation and body weight, but it does not currently offer a direct intervention for humans.

Central nervous system (CNS) activation of GLP-1 receptors by peptides such as GLP-1, oxyntomodulin (OXM), or glucagon (GCG) directly increases brown adipose tissue (BAT) thermogenesis via sympathetic nervous system signaling, independent of changes in food intake or peripheral insulin sensitivity.

Central GLP-1 receptor activation (via drugs like GLP-1 agonists) boosts brown fat activity to burn energy, separate from just making you eat less. This mechanism requires the drug to act on the brain, not just the gut.

Oxyntomodulin (OXM) requires functional GLP-1 receptors in the CNS to induce brown adipose tissue thermogenesis, despite also binding to glucagon receptors.

If using Oxyntomodulin (or dual agonists with strong OXM activity), the GLP-1 receptor pathway is essential for activating brown fat. Simply activating glucagon receptors is not enough to trigger this specific fat-burning mechanism.

Germline loss-of-function PTEN mutations cause constitutive insulin sensitivity, resulting in significantly lower fasting insulin levels and higher glucose disposal rates despite the presence of obesity.

This finding highlights that metabolic health (insulin sensitivity) is genetically regulated and can be preserved in obesity if specific pathways (like PTEN) are active. It suggests that BMI alone is an insufficient predictor of metabolic risk for all individuals, particularly those with specific genetic profiles.

PTEN haploinsufficiency leads to increased adiposity and obesity without corresponding changes in lean body mass or fat distribution patterns compared to matched controls.

Individuals with PTEN mutations tend to have higher body fat percentages due to genetic factors, not just lifestyle. This suggests that standard weight-loss advice may need to account for genetic predispositions to adiposity.

Thyroid hormone (T3) accelerates skeletal muscle contraction and relaxation rates by stimulating the expression of fast myosin heavy chain isoforms (MYH2, MYH1, MYH4) and sarcoplasmic reticulum Ca2+ ATPase (SERCA1a).

If you have hypothyroidism, treating it to normal levels may help restore normal muscle speed and function, as thyroid hormone directly controls the proteins responsible for contraction speed. However, for healthy individuals, manipulating thyroid levels is not a standard or safe performance enhancement strategy.

Thyroid hormone (T3) increases skeletal muscle mitochondrial biogenesis, oxidative capacity, and resting metabolic rate by upregulating PGC1α, UCP3, and mitochondrial enzymes.

Normal thyroid function is essential for healthy muscle metabolism and energy production. If you have hypothyroidism, treatment can restore mitochondrial function and energy levels. Do not attempt to increase thyroid levels beyond normal ranges for metabolic boosting, as this can lead to muscle wasting and other health issues.

Thyroid hormone (T3) regulates skeletal muscle myogenesis by controlling intracellular T3 levels via D2 and D3 deiodinases, which determines satellite cell proliferation and differentiation.

Proper thyroid function is necessary for effective muscle repair and regeneration after injury or exercise. If you have thyroid issues, addressing them may improve your body's ability to repair muscle tissue.

Inhibition of the epigenetic regulator LSD1 in adipocytes activates energy-expenditure genes (such as PGC-1α and PDK4), thereby increasing mitochondrial respiration and lipolysis.

This research identifies LSD1 as a key epigenetic regulator that suppresses energy expenditure in fat cells. Inhibiting LSD1 (through genetic knockdown or specific inhibitors like tranylcypromine) reverses this suppression, leading to increased mitochondrial activity and fat burning. While direct LSD1 inhibition is not yet a standard human therapy, this mechanism highlights the importance of cellular FAD availability and epigenetic control in metabolic health.